without going through the process of measuring a specific kind of yarn,

without being forced to knit to a calculated number of stitches per row and

without being dependent on a certain kind of yarn.

That's why I decided to do something with solid colors. The piece is knitted all in garter stitch, short row ridges in contrast colors are used to create this pattern. To get to the point where you start the short row, you have to slip a number of stitches without knitting them. I can imagine that you also can achieve a similar effect it with intarsia, but you'd need more skeins (bobbins) for this - up to 3 of the main color.

By the way, this is my hundredth (100th!) pattern on Ravelry! I must admit that I'm rather proud ...

a total of 160 grams of Sports weight yarn in three colors - called main color (MC, light orange in the photos - about 110 grams), contrast color 1 (CC1, white in the photos - about 25 grams) and contrast color 2 (CC2, pink in the photos - also about 25 grams)

4mm knitting needles

a tapestry needle to weave in ends

Gauge and Size

When knitting the piece you will have unnevenness due to the number of rows at certain points. This will even out in the end - however, after blocking some parts will be more stretched than others. That's why I chose to give you gauge with an unblocked piece: Unblocked and knitted in garter stitch 19 stitches gave 10 cm in width and 18 ridges (i.e. 36 rows) gave 10 cm in length.
The finished piece is 82 cm long ("elbow-to-elbow") and 38 cm wide (i.e. has a circumference of 38 cm at the arms).
If you have different gauge or a want to knit another size, there are some suggestions how to change the size at the end of the pattern.

Wrap and Slip Front Stitch (w+sfs): Bring the new working yarn to front (see photo 1). Slip the next stitch as if to knit (photo 2). And bring the yarn working yarn to back (photo 3) and continue knitting (photo 4). This is used to attach the new working yarn of a new color to the stitch in front. It's not a wrap before a turn, but a wrap before you start knitting in this direction.

In the row above this w+sfs wrap, this stitch is knitted through the back loop as follows: pick up the wrap with the right hand needle (photo 1) and place it on the left hand needle (photo 2); then knit it through the back loop (photo 3). In the instructions the stitch that was wrapped like this will be referrred to as wfs-stitch.

Instructions

Short Version
Some explanations:

The piece is knitted in garter stitch ridges - one ridge is knitted in the main color, followed by a short row ridge in CC1, a ridge in MC and a short row ridge in CC2.

The contrast color short rows always move 2 stitches from one use of the color to the next:

During the first half of the pattern CC1 starts at the start of the row and moves 2 stitches further towards the end,

CC2 starts at the end of the row and then moves 2 stitches further towards the beginning of the row

During the second half of the pattern the contrast colors "move" in opposite directions.

The yarn in contrast colors is carried up on the WS of the pattern. Since the distance between the starting points of the short rows is usually 2 stitches and one ridge, the floats are not too long.

CO 70 in MC

Ridge 1 (MC): sl1, k to end, turn, sl1, k to end
Ridge 2 (CC1): sl1, k25, w+t, k 26
Ridge 3 (MC): sl1, k to end, turn, sl1, k to end
Ridge 4 (CC2): sl to 27 sts before end, w+sfs, k26, turn, sl1, k25, sl to end
Ridge 5 (MC): sl1, k to wfs-stitch, ktbl, k to end, turn, sl1, k to end
Ridge 6: (CC1): sl to the stitch where you started CC1 the last time (i.e. 4 ridges before), slip one more stitch, w+sfs, k26, w+t, k26, sl to end
Ridge 7 (MC): sl1, k to wfs-stitch, ktbl, k to end, turn, sl1, k to end
Ridge 8 (CC2): sl to 3 sts before the stitch where you started CC2 the last time (4 ridges before), w+sfs, k26, w+t, k26, sl to end
Repeat ridges 5 to 8 until ridge 8 starts without slip stitches (i.e. you start knitting with CC2 at the beginning of the row).

Now you nearly knit the same sequence backwards, i.e.
Ridge 1b (MC): sl1, k to end, turn, sl1, k to end
Ridge 2b (CC1): sl to 27 sts before end, w+sfs, k26, turn, sl1, k25, sl to end
Ridge 3b (MC): sl1, k to end, turn, sl1, k to end
Ridge 4b (CC2): sl1, k25, w+t, k 26
Ridge 5b (MC): sl1, k to wfs-stitch, ktbl, k to end, turn, sl1, k to end
Ridge 6b (CC1): sl to 3 sts before the stitch where you started CC1 the last time (4 ridges before), w+sfs, k26, w+t, k26, sl to end
Ridge 7b (MC): sl1, k to wfs-stitch, ktbl, k to end, turn, sl1, k to end
Ridge 8b (CC2): sl to the stitch where you started CC2 the last time (i.e. 4 ridges before), slip one more stitch, w+sfs, k26, w+t, k26, sl to end
Repeat ridges 5 to 8 until ridge 8 starts without slip stitches (i.e. you start knitting with CC1 at the beginning of the row).

End with an MC ridge and BO.
Weave in ends an block.
Fold lengthwise and seam the arms.

Weave in ends and block! The picture below shows the piece on the blocking board.
Fold lengthwise and seam the arms.

How to Adapt the Pattern to Another the Size
As you may have noticed when reading the pattern. the contrast color short rows always move 2 stitches from one use of the color to the next.
During the first half of the pattern CC1 starts at the start of the row and moves 2 stitches further towards the end, while CC2 starts at the end of the row and then moves 2 stitches further towards the beginning of the row.
This means that the first point where you start the short row with CC2 is as far from the end as the length of the short row (in the pattern above the row is 70 sts wide - and the CC short rows are always 26 sts wide, that means the first start of the CC2 short row starts with 70-26=44 slip stitches - or rather 43 slip stitches and the 44th one is wrapped from the front).

So if you just want to lengthen the piece, you could chose to make the short rows shorter than 26 sts, this means you need more rows until the last short row reaches the other end of the complete row.

Or if you just want to widen the piece, you can chose to cast on more than 70 sts and adjust the length of the short rows, e.g. CO 80 sts and make the short rows 36 sts long. That way you still need the same number of rows as specified in the pattern. Please note that here you need to start the first short row in CC1 at the stitch that is as far from the end of the complete row as the short row is long.

I don't know what an "intermediate" or "advanced" pattern is ... Here's the list of skills you need to knit this pattern:- knitting garter stitch- slipping stitches - doing "wrap and turn"s - and something similar from the front which is explained in the pattern- counting